Method of and apparatus for producing and reproducing sound



June 16, 1 936. H NUTTALL 2,044,223

METHOD OF AND APPARATUS FOR PRODUCING A ND REPRODUCING SOUND Filed Oct. 25, 1928 4 Sheets-Sheet 1 Snow doc cfamea H A ZzZZaZZ;

16, 1936. NUTTALL 2,044,223

METHOD OF AND APPARATUS FOR PRODUCING AND REPRODUCING SOUND H gwmmtoz JZzmes [Y MZZQZZ June 16, 19 J. H. NUTTALL METHOD OF AND APPARATUS FOR PRODUCING AND REPRODUCING SOUND Filed Oct. 25,

1928 4 Shee .sSheet 5 x gwuento'o 0677285" 12'. A uZZaZZ June 16, V J H t 2,044,223

METHOD OF AND APPARATUS FOR PRODUCING AND REPRODUCING SOUND Filed 001 25, 1923 4 Sheets-Sheet 4 i .lJa.

gnwntot 71 /zzmes :Y M15302? Patented June 16, 1936 UNITED STATES METHOD OF AND.APPARATUS FOR PRO- DUCING AND REPRODUCING SOUND James H. Nuttall, Glendale, Calif. Application October 25, 1928, Serial No. 314,940

26 Claims.

This invention relates to musical instruments and has for its principal objects the production of light waves of varying intensities corresponding in vibrations to those of the sound which it is desired to produce, and the conversion of the light waves so produced to sound, and the provision of a mechanism for producing sounds by sucha process of tonal quality and pitch as determined by automatic control means or hand operation.

In one phase it is particularly directed to the process of and apparatus for producing light waves of predeterminedfrequency, intensity and sequential variation, entirely under 'the control of the operator, in contrast to apparatus now in use for reproduction of sound through the medium of light and photography.

Further objects are to produce such a mechanism which may be contained in small space,

which will be simple to construct, maintain and operate, and by means of which any desired combination or sequence of pitches and tone qualities may be obtained.

It has for a further object the faithful reproduction of a desired sound or tone at any pitch desired.

Another object is the method of sound production consisting in impressing the vibrations upon a moving air stream and in varying the movement of this airstream in synchronism with the vibrations.

Another object is to provide such an instrument whereby the tonal quality produced may be easily changed to meet various requirements,

and whereby an infinite variety may be obtained by simple substitutions.

Another object is to produce such manufactured sound waves of pure tone quality and pitch without mechanical noise.

With. these and other objects in view the invention comprises the process and apparatus for the production of light waves of'predetermined variation, amplitude, and period and the conversion of such waves into sound, all as illustrated in the accompanying drawings and as will be finally pointed out "in the claims.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will hereinafter be morefully described and claimed and illustrated in the accompanying drawings, in which:

\ Fig. l is a diagrammatic arrangement of the invention for automatic and associated manual production of music or sound.

Fig. 2 is a more detailed diagrammatic representation of this invention.

Fig. 3 is a fragmentary plan view of one of the light wave producing units.

Fig. 4 is a transverse section fled form of the light wave production and conversion device.

Fig. 5 is an enlarged fragmentary detail of the pitch determining disk.

Fig. 6 is a fragmentary detail illustration of the tone determining film.

Fig. '7 illustrates a means of producing the tone film of Fig. 6.

Fig. 8 illustrates a means for obtaining a variation in tone efiect.

Fig. 9 illustrates a resonant .tonal producing and amplifying device Fig. 10 is a section on line lll-l0 of Fig. 9.

Fig. 11 is a fragmentary section on line lI-ll of Fig. 3.

Figs. 12 and 13 illustratemodified forms of tone-quality control.

Fig. 14 illustrates a modified form of pitch control.

Figs. 15a and 15b represent vibrations.

Figs. 16a and 16b represent sections through tone films.

Figure 1'7 is an illustration of additional tone regulating means.

Referring now to Figs. 1 and 2, which illustrate a preferred form of my invention, I provide an automatic control means 20, a manual control means 2|, 2. light wave producing means 22, means for converting the light waves formed by the means 22 to electrical waves comprising converting means mechanism 24.

The automatic means 20 and the manual means 2| may operate in conjunction, or either may be operated separately, the means 21 being illustrated as an organ keyboard comprising a series of keys 25 for the control of the pitch of the sound produced; and which may be arranged in banks comprising manuals and pedals, as in the usual organ keyboards.

For controlling the tone quality and character a series of stops 26 are provided and each of these stops is shown/as including a switch 21 interposed between a source of current supply 28 and a tone determining means 29.

Preferably I may provide a series of light wave producing means 22, as shown in Fig. 1, each of such wave producing means having associated therewith a plurality of tone determining means forms of musical through a inodi- 23, and a sound producing "the conversion means 28 all connected and controlled from a common source incorporating the automatic control means 20 and the manual control means 2| so that I may simultaneously produce through the operation of the various stops a succession of sounds or diiferent tone quality or by the operation of the various manuals produce simultaneously separate melodies or accompaniments in different or similar tone quality. To such effect I may, as shown diagrammatically in-Fig. 1, connect one bank of stops, to the tone determining means 29 upon one of the means 22 and another bank of stops to the means 23 upon another lightv wave producing means 22, and I may control one or the means 22 from one of the keyboards and another of the means 22 from another of the keyboards.

I may also prefer to provide several of the sound producing units 24 which may be situated in various parts of an auditorium and to which I may switch some or all of the sounds.

The automatic control means is best illustrated in Fig. 2, and includes a source of light 38, a series of light sensitive cells 3|, positioned so as to receive light energy from the source 30, as through an opening 32 in the cell covering 3 la. a

An opaque strip 33 of flexible material, such as paper, metal or film, and provided with light passages such as transparent portions or openings as at 34 is adapted to pass between the light source and the cells 3|, and as the light openings 34 in the strip 33 pass over the openings 32 rays from the light are transmitted to the cells 3| generating a current variation therein.

Certain of the cells 3| are connected to relays s own diagrammatically at 35, and others are each connected to a relay as 38. It will be understood that each of the cells 3| is connected to a separate relay, only two of such relays being shown in the drawings for the sake of simplicity.

The current variation generated in the cells 3| operates to close either one of the relays 35 or one of the relays 36, depending upon the particular cells exposed to the light rays.

Any of the relays 35 operates to close the circuit between the source of current supply 28 and one of the tone determining means 23, producing the same eiIect-as the s p 28. The relay 38 operates to close the circuit between the source of current supply 28 and a means 31 for efi'ecting the pitch control operation. This relay closes the circuit between the same members that are closed by the operation of 25, there preferably being a relay 33 for eac stop 26 and a relay 36 for each key 25.

' The light wave producing means 22 may comprise a source of light energy 38., asemi-confining shield 39 for such light, a series of pitch shutters 40 movably mounted on guides 48a and adapted-to be controlled by a series of means 31, shown diagrammatically as electrically operated solenoids resisted by tensile springs 31b, and adapted to close the opening in the shield 33 at certain points to prevent the pasage of light to the conversion means 23. A housing 31:: is provided for means 31.

A vibration producing device 4| is interposed between the pitch shutters 40 and the conversion means 23. A secondary shutter 42 is interposed between the vibration producing device 4| and a tone film 43, also between the light source 38 and g 23. An opaque shutter 42a ymay be also provided controlled by one 01' the means 31 and an associated stop'28.

The vibration producing means 41 is illustrated a corresponding key 7 in Figs. 2, 3 and 5, as comprising a disk 44 of transparent material covered with an emulsion 45 having an opaque portion 46 and a series of transparent portions 41.

The disks may also be made of any opaque material, such as paper, metal, rubber or other composition. and the light openings provided by appropriately spaced perforations, as at 41', Fig. 4.

outwardly from the center, representing a pitch an octave higher. Intermediate rings are provided with openings to represent the intermediate note, that is the twelve rings would represent the twelve half tones of each octave.

Practical consideration may necessitate grouping various ranges on each disk, that is, on any one disk every third or fourth note may be an octave higher instead of by steps of twelve, intermediate tones appearing on other disks revolving at other speeds. This is to secure more accurate pitch production with a minimum number of perforations:

For each ring of openings there is one of the pitch shutters 40. Thus shutter 40 may extend entirely around the disk as shown in Figure 3, so as to control the transmission of light to one of the light sensitive cells 48' of each of the conversion means 23, or may be a shutter as illustrated in Fig. 14, at 48 and control but one of the cells 48.

As the-disks 44 are rotated at predetermined speeds, light from the source 38 passes through any oi the shutters 40 which are open and in a series of rays or beams passes through the openings 41 and across the tone film 43 onto the cells "producing a series of light vibrations, the frequency of which depends upon the speed or the disk 44 and the spacing of the light openings 41. Inasmuch as these light rays pass through the tone film 43 in their passage across the cells 48, they are modified by the shading of this tone film to produce the vibrations desired in the light ray for the final tone character. 1

Obviously I may provide one disk 44 for each octave or for any number of octaves and provide a series of such disks rotated at various speeds to provide for the range of pitches desired, all of the disks being identical in construction and spacing of light openings, of manufacture.

I also provide means for varying the speed of rotation of the disk for changing the key or pitch of the whole range included on that disk. Such speed changing devices are of numerous kinds and well known in the variousarts and are therefore but diagrammatically illustrated.

In Fig. 1 I show a variable resistance speed control 52 on the driving member 83. One oi'the motors .33 may be 44 and the motors properly synchronized driving each disk through appropriate gearing 54; or the various disks may all motors 83 and a single set of gearing 54 and the various units connected by driving connections, as at 84c.

It is thus possible with such a speed changing the light energy over resulting in greater economy.

provided for each 01' the disks I be driven from one 01 the device to simply and easily change the pitch of the whole instrument to that of any other instrument played with it at the will of. the operator. Pitch is unaffected by temperature variations or other natural phenomena, but is entirely may control a resistance 49 in this circuit,-whereby the shutter action may be controlled to bring an intermediate portion over the tonefilm. With the resistance all out of the circuit, the shutter will move throughits full range to place a transparent portion in the light path. Thus as certain of the stops 26 each control such a shutter .over a tone film, means is provided for throwing in or out of action any tone control means 28 desired by manipulation of these stopscontrolling both the light source and the shutter 42. Others of the stops 25 control resistance 49 and others a resistance 59 controlling the light intenslty.

The shutter 42 is preferably in the form of a shaded disk or segment, as illustrated in Fig. 8,- in which the various portions of the shutter adapted to be interposed between the light rays and the conversion means 23 vary in light transmitting quality from a transparent portion to an opaque portion, so that by varying the resistance 49 various portions of the shutter may be brought into the path of the light rays to vary their e1.- ifect upon the cells 48 and hence upon the final sounds produced.

Various shadings may be used upon this shutter to obtain the desired effects, such as by having the portion overlying the cells corresponding to the bass notes semi-transparent, while the portion covering the higher note cells fully trans-- parent a dimuendo effect is produced in the bass notes. Tone films also may be mounted thereon. Other desired modifications may be introduced by suitable shadings of this shutter, such as indicated by the shading of the illustration. Similar effects may be obtained by providing for the movement of the light source toward and away from the means 23 so as to give a greater or less intensity of light or the lights may be tilted to give a graduation effect between the various pitches, a means for'this purpose being diagrammatically shown in Figure 17. The light source 38a is supported at each end by links 38b. These links are each attached to an arm of a bell crank 38c pivoted as at 38' to any stationary portion of the instrument. Another arm of the bell crank is connected by links 38d to a lever 38c pivoted at 38) within reach of the operator. Counterweights 38g attached to extensions of the bell crank arms may be used to counterbalance the weight of the light source and its connections and make operation easier.

Such mechanism will'produce variation in the volume of sound produced from each tone determining means 29, so that certain parts of. the

24. Such volume control may comprise a vari-- able resistance 5| interposed in the amplification circuit in the usual manner. The cell 48 may be any of the types of light sensitive cells whereby changes in intensity of rays from the light source '35 produce similar changes in electrical energy transmitted therethrough from a source 55. Selenium and chlorine cells are examples.

The current so produced fluctuates electrically in the same manner as the light rays fluctuate which have been impressed upon the cell 48 and these variations are amplified, by well known radio amplification means illustrated diagrammatically as transformers 50, A and B batteries 6] and 62 andtubes 53. It will be understood that any appropriate amplifying circuit may be used.

This amplified current 'is' conducted to the power unit 54 of a specially constructed loud speaker 55, illustrated in Figs. 9 and 10. This -loud speaker comprises the usual electro-magnet and is shown with a diaphragm 51. The armaturetype of speaker may be used in the same manner.-- This diaphragm 6'5 controls the motion of two concentric disks 6!! and 69 through a bifurcated connecting link 10. The disks 68 and 69 are adapted to oscillate upon a shaft H at the entrance to the sound-chamber 12 of this speaker. One prong oi the link 10 connects through a pin 13 with one of. the disks and the other prong connects with'a pin I4 fixed to the disk 59 on the opposite side of the central axis from the pin 13.

The pin 14 passes through a slot 15 in the disk 58 and allows for relative movement of the disks. These disks are interposed between a chamber I6, adapted tobe continuously supplied with air under pressure through a pipe 11, and the chamber 12;and are provided with a series of segmental openings so arranged that in the rest position of the diaphragm 61 the openings of one disk are closed by the uncut portion of the other disk.

As the diaphragm in is vibrated the disks ea and 59 oscillate, permitting the openings to overlap to a greater or less degree, depending upon the amplitude ofthe oscillations and thus effect a vibratory air flow from the chamber 16 to the.

chamber 12, setting up a dynamic air vibration. The sound waves produced by the diaphragm or armature of the speaker are therefore impressed upon a moving air column which in itself is given a vibratory flow by the opening and closing of the openings. This flow variation being synchronized with the sound waves provides an amplifying eifect and gives a true reproduction of the- In place of the disks,

music of wind instruments. either plain or interm'shing shutters, or oscillating ported tubes or cones maybe employed in a like manner.

Connected to the chamber 12 are preferably five sound pipes 18 of varying lengths, the lengths being such that resonant effects are produced for all tones, that is'it has been determined that if the lengths of these pipes are in the ratio of eight feet, seven feet seven inches, seven feet three inches, six feet eleven inches and six feet seven and one-half inches approximately, that one of these five will provide resonance for all pitches.

An ordinary cone or loud speaker air column may, however, be employed where the added volume or resonant effect is not needed.

Referring again now to the means 22, and the disk 44 comprising a portion of such means, above the shutters 40 are placed a series'of radially extending light chambers, each formed by the light shield 35 and containing the light 38. Directly I sufiicient.

beneath each of these chambers and beneath the disk 44 is located one of the means 28 comprising a series of light sensitive cells 88, there being one of these cells for each of the concentric rings of light openings 41. If, however, it is desired to play single notes one cell alone adapted to be exposed to the light rays from all rings would be The cells 48 may be continuously energized by a battery 55, or other current source.

Other means of the tone control are diagrammatically illustrated in Figs. 12, 13 and 14.

Referring to Fig. 12, two of the converting means 23 are shown at 85 and 86 respectively, each having light sensitive cells 48 and a tone film 43. In this method of control'the keys 25 are interposed within the light sensitive cell circuits.

All of the cells 48 for each pitch are connected in parallel and the key switch 25 is thus in series and controls all of the cells of the pitch which it represents. The other leads from the cells 48 for each of the means 23 are connected together and the combined circuit is led through tone control stops 26 to the sound producing mechanism 24, diagrammatically represented by the primary coil 81 of a transformer 88, the secondary of such transformer being connected to the usual amplifying apparatus, as previously designated. Thus stop 89 will bring intoplay the converting means 85 and stop 98 the converting means 88.

While only two of the converting means 23 and associated stops 26 are illustrated it will be understood that any number may be so connected. Thus upon pressure of the key 8i the particular cells 92 and 93 of the converting'means 85 and 86 and of similarly situated cells of other converting means will be connected through the key 8i to one side of the transformer coil 81. However, inasmuch as the stop 88 is .open, and the stop 89 is closed, any light energization of cell 98 will not affect the transformer 88 while all energization of the cell 92 will be transmitted directly to the tion means to the sound producing mechanism 28.

In Fig. 13 the keys25 are in circuit between a.

light source which is energized only upon pressure of the proper key.

The return lines from the light sources pass through control stops 25 in the same manner as in Fig. 12, the stops, however, in this case controlling the banks of light sources rather than the banks of cells.

In Fig. '1 is illustrated a means of producing the so-called tone film. Supposing that it is desired to produce acertain tone efiect, such tone e fect may be originally produced in any pitch and is received by a microphone shown diagrammatically at I88, which, through a variable resistance I8 I varies the intensity of a light source I82 which receives its energy from a source of current supply I83. 7

The light source I82 is placed within a light shield I84, within which is placed a rotatable disk I85 controlled by a motor or other means I86 and which contains a transparent or slotted portion I81 through which a narrow band of light may be directed upon a sensitized film I88 also mounted upon a disk I89 which is rotated by means I III, which may be a motor or other power driven apparatus.

The motors I88 and I I8 may be synchronized so transformer 88 and hence through the amplificathat desired relative speeds of rotation are obtained.

Additional light shields I I I are provided for restricting the exposed portion of the sensitized film I88.

It will be readily apparent then as the slot is rotated past the openings in the disk III that a segment of the sensitized film will be exposed through the slot I81, the speed of rotation being varied to correspond with the pitch of the note being reproduced so that one complete period is recorded upon the film and this segment is later developed and removed and a reproduction thereof may be used as the tone film 43.

A hand switch I I2 may be provided for closing the light circuit when the desired quality of tone ,is being sounded.

It is also obvious that other methods may be used to produce this tone film, in fact means may be used to so-shade the tone films either mechan ically or manually that any desired eiIect can be produced.

It will be apparent that a tone film so produced will vary in translucent properties across the segment and by properly proportioning the disks for producing this film and the speeds during this production, in accordance with the spacing of the light openings on the disk 48, a tone film is produced which, when in position under the disk 48, will have upon it one complete tone period in the distance between the light openings of the various rings above it and on the disk 84. That is, the circumferential distance between the light openings of any ring will equal the corresponding length of one vibration period on the tone film segment beneath the particular ring of openings.

The relation between the relative rotations of the disks I 85 and I88 and the spacing of the concentric rings of transparent portions 41 of the disks 88 may be so related that a period on the tone film will exactly correspond to the spacing of the light openings 81 in the ring, which will be directly above it when used as a tone film, or the period may be lengthened or reduced by any of the well known photographic processes to the desired, size; likewise by various photographic processes vibrations may be superimposed or other variations made. Films may also be used in combination to produce double effects or compound vibrations.

The principle of the tone film is illustrated in Figs. a, 15b, 16a and 16b. Fig. 15a is a diagrammatic showing of a pure tone vibration,

Fig. 15b of an instrumental tone, embodying the basic pure tone with variations and harmonics. A sound such as illustrated in Fig. 15a would produce some such film emulsion as illustrated by the section of Fig. 16a in which the stippling illustrates variation in translucence. A sound as similarly shown in Fig. 15b would produce some such film as shown in the section Fig. 16!).

.It is obvious that a light beam passed across this film would impress upon. a cell beneath varying light intensity corresponding to light transmitting qualities the various portions of the film, and that a single ray passing over this film would vary its intensity in its passage in the same sequence and proportionate variation as the vibrations of the original sound used to. produce 7 the film. Also it will be apparent that the pitch of the tone produced will entirely depend upon the number of rays passed over this film per second regardless of the pitch used to produce the original tone film.

Only one complete sound wave record is preterably used, although any number may be used by suitably spacing the beams traversing the film, such as by changing the speed of the disk 44 or by varying the spacing of the light openings or this disk.

This tone film is an important element of this invention as it provides for the imposing of any desired light variation upon the elemental series of light rays to produce a final toneof the character desired. And further the periodicity of the tone film variation is determined by and must therefore exactly correspond to that of the spacing and speed of the light beams delivered through the disks M. It is given to each of the beams in turn in exactly the same manner.

In order to provide for the intermittency or the beams, so that the sound produced will be the resultof a continuous vibration, the tone film would be cut, or be made effective the width of the light beam more than one single complete vibration or an even multiple thereof. That is, in Fig. 15b the effective portion exposed to the beam would be between the lines a and b while a single vibration would be represented by the distance a to c. The distance D to 0 would be the width of the light beam. These distances vary, as before stated, along the length of the tone fllm to accommodate the variation of the spacing of the light openings in the successive circles of the disks 44.

Thus as one beam is coming onto the tone film along the portion represented by b to 0. another beam is passing off ofthe film on the-same portion of the vibration adjacent a. If one beam is one third the way on, the other isv one third off, so that the total light affecting the cell is the same at all times as if one beam were continu ously acting on it through the tone film, and the vibrations of the cell are continuous and without interruption. i 1

Such construction provides for a true production of both the pitch and tone quality.

It will be readily observed that simple changes may be made throughout the instrument to produce an almost infinite .variety of music. Changes in speed of the disks 48 will change the pitch range of the entire instrument, changes in gearing may be made to change the range of any one or more of the light wave producing means 22 alone. Insertion of new tone films 43 or shutters 42 will change the quality of tone for the particular stop 26 without affecting any other part of the instrument.

Corresponding changes on other'musical instruments involve extensive alteration; such as .on an organ, for instance, in regard to pitch,

every individual pipe must be changed and separately tuned. Change of the tone quality produced by a particular stop necessitates thereplacement of every individual tone producer with associated wind chests and other parts to suit the new effects installed. Such changes involve great expense. In this invention the same change: involve merely the adjustment of speed of the disks 44 for the pitch change and the insertion of a new tone film 43 of the required quality for the stop change.

It will be understood that minor changes in the size, form and construction of the various parts of my improved musical instrument may be made and substituted for those herein shown and described without departing from the spirit "of my invention, the scope 01' which is set forth in the appended claims.

source and said converting means for varying the intensity of the rays to vary the volume of the sound.

2. A musical instrument including a light source, means for converting light variations intosound, a movable member interposed between said light source and the converting means, said member being provided with transparent portions and opaque portions, whereby light beams are intermittently traversed over the converting means upon movement of the member, means for effecting a predetermined sequence of energy variation in the rays during such traverse, and a, second member adapted to be interposed between the first member and the convertin means for varying the intensity of each beam during its passage over the converting. means.

3. A musical instrument including a. light source, means for converting light variations into sound, a movable member interposed between said light source and the converting means, said member being provided with transparent portions and opaque portions, whereby light beams are intermittently traversed over the converting means upon movement of the member, means for effecting a predetermined sequence of energy variation in the rays during such traverse, a second member of variable translucencyadapted to be moved between the light source and the converting means to vary the intensity of the light beams,- and means for controlling the 40 movement of said second member.

4. A musical instrument including a ligh source, a plurality of means for converting light variations to sound, means for traversing a successive seriesof light beams of predetermined frequency across said converting means, means for producing predetermined. sequences of variation in light energy of such beams during their passage across said converting means, and

means for selectively determining the character 50 of such variation.

5. An automatic musical instrument including a series of light sensitive cells, means for intermittently exposing certain of said cells to the light source, a sound producing device, electrical connections between the cells and the sound producing device, whereby exposure of certain selectively varying the frequency of the rays, a

separate means for creating a pre-determined sequence of variation of the quantity of light received by the converting means during its exposure to each ray, said variation bearing a fixed relation to the frequencies of each ray.

7. A musical instrument. including means for generating intermittent light rays at. a plurality of frequencies, means for converting light variations into sound, and means for selectively predetermining the quantity oi! light energy received by the converting means at certain frequencies in one degree and that at certain other frequencies in another degree.

8. A musical instrument including means for generating intermittent light rays at a plurality of frequencies, means for converting light variations into sound, means for selectively predetermining the quantity of light received by the converting means at certain frequencies in one degree and that at certain other frequencies in another degree, and means for selectively controlling said last named means.

9. Means for Varying the quantity of light in each or a, series of rays of variable frequencies comprising a member interposed in the path of such rays, and a light record thereon of a particular tone quality, each portion of said record bearing a definite relation to the frequency 01' the rays aflected thereby, whereby each ray passes through the same intensity variations in time sequence proportionate to its time or exposure to said record.

10. A musical instrument including a light source, a rotatable disk provided with opaque portions and with a plurality of series or circumferentially spaced transparent portions, means for converting light variations into electrical variations and exposable. to light rays passing through such transparent portions, and a radial film between said light source and said converting means having a tone record thereon adapted to vary the energy of light rays passing through a plurality of said circumferential series of trans-' parent portions, each portion or said tone record bearing the same relation to the circumferential spacing of said transparent portions afl'ccted thereby.

11. An automatic musical instrument comprising a series of sound generating units, means for causing such units to produce sound, relays for controlling the admission of the electricity to said means, a light source, a light sensitive cell, electrical connections between such light sensitive cell and said relays, and means for automatically controlling the admission of light to said cell.

12. A musical instrument including a plurality of light sources, a plurality of light sensitive cells adapted to receive light from such sources, a rotatable disk interposed between the light sources and the cells and an operating shutter controlling the passage of light to the cells, said shutter being provided with spaced transparent portions and opaque portions whereby the light flow between the light sources and the cells may be simultaneously controlled.

13. A musical instrument comprising means for generating intermittent light rays, means for converting light vibrations into sound vibrations and "resonators associated with the converting means, said resonators including pipes or column lengths substantially in the proportions of 192, 182, 174, 166 and 159 adapted to produce on all scale.

ing a. series or sound generating units, electrically operated means for controlling the bitch of the sound produced thereby, electrically operated means for controlling the quality of the tone produced thereby, a source of electrical pitches oi the musical 14. An automatic instrument includenergy, a light source, a series of light sensitive cells, electrical connections between certain of said cells and the means for controlling the pitch, electrical connections between others of said cells and the quality controlling means and means for controlling the exposure of said cells whereby the quality and pitch of the sounds pro duced may be simultaneously varied in a predetermined manner.

15. A tone film for varying the energy in a series of light rays including a segmental body of variable translucency, the sequence of translucency variation being constant in ratio along various circumferential lines.

16. In combination with a. source of light and a means for converting light to sound in a. musical instrument, an opaque disc having light openings therein arranged in circumferential series, the series having difierent numbers of openings therein, means for rotatlng said disc,

17. In a musical instrument, a source of encrgy, means for converting energy variations into sound, a series of means adapted to transpose constant energy from such source into pulsations representing a musical tone and to energize said converting means therewith, driving means for said transposing means, connections between said driving means and said transposing means of various ratios, whereby similar transposing means will producevarious ranges of pitch.

18. A musical instrument as described in claim 1, and including means for selectively controlling said intensity varying means to control the volume or sound.

19. A musical instrument including a. light source, means for converting light variations into sound and adapted to receive rays from said source, means for producing predetermined frequencies of such rays. means for varying such rays in accordance with a predetermined tone quality, and means interposed between said light source and said converting means for selectlvely varying the character of said tone quality.

20. A musical instrument including a light source, means for converting light variations into sound and adapted to receive rays Irom said source, means for producing predetermined frequencies of such rays, and means. for varying such rays in accordance with a predetermined tone quality, said last named means including a member having a representation of a tone quality thereon adapted to vary the energy of the light rays in accordance with such tone quality,

said means being movable into and out of posiplurality of predetermined frequencies, a plu- 65 rality oi means each adapted to vary the energy of rays of a plurality of frequencies in accordance with a predetermined tone quality prior to reception by said converting means, and means for selectively rendering efl'ective any or said energy varying means.

22. A musical instrument including a light source, means for converting light variations into sound, means for generating light rays 01' predetermined frequencies, a plurality of means 75 each adapted to vary the energy of such rays in accordance with a predetermined tone quality, means for rendering effective any of said energy varying means, and means for simultaneously controlling the conversion to sound of rays of predetermined frequencies as affected by a plurality of said energy varying means.

23. A musical instrument including a light source, means for converting light variations into sound, means for generating light rays of predetermined frequencies, a plurality of means each adapted to vary the energy of such rays in accordance with a predetermined tone quality prior to reception by said converting means, and

means for rendering independently effective a plurality of said energy varying means.

24. A musical instrument including a light source, means for converting light variations into sound and adapted to receive light energy from said source, means for generating a plurality of groups of light rays each group of a plurality of predetermined frequencies, means for varying the energy of' each of such groups of rays in a manner representative of a predetermined time quality, and means for simultaneously controlv ling the conversion of light energy from a plurality of such groups to sound.

2Q. A musical instrument including a plurality 01' light sources, means ior converting light variations to sound and adapted to receive light from such sources, a plurality of means for intermittently varying the light energy received by said converting means in a predetermined manner, means for creating a predetermined frequency of such variation, and control means adapted to simultaneously permit the passage of light energy from a plurality of such light sources to the converting means, and means for selectively controlling the energy varying means to render effective desired ones thereof.

26. A musical instrument including a plurality of light sources, converting means adapted to receive light from such sources and to convert variations therein to sound, a rotatable disc interposed between the light sources and the converting means and having a series of circum- Ierential series of light openings therethrough, and a shutter including spaced opaque portions each controlling the passage of light iroma light source to the converting means, whereby the reception of light by the converting means ,irom all sources is simultaneously controlled.

JAMES H. NUT'IALL. 

